Sakura's strength can break Yamato's wood easily. During a filler arc, an invasion in the leaf and everyone was split up to battle. Yamato battle this stone strength guy who can break his wood defense, even though his strength is shown no where near Sakura's level.
But Yamato has a higher chance of winning against Sakura still, although not too much higher. The yin seal give Sakura an impressive reserve of chakra, when she uses it all, it will take a while for it to rejuvenate.
Yamato's greatest advantage against Sakura is his ability to fight long ranged, whereas Sakura is a close ranged fighter, and is at a disadvantage. His other advantage is his battle experience, although Sakura's "base" intelligence is most likely greater than his, as a given for being one of the best medical ninja in the ninja world.
So I'd say Yamato wins this one, mid-high or most likely mid difficulty.